Many, if not all, of us have had the experience of walking into a room and forgetting exactly what it is we came in there to do. (Except in the case of the bathroom, where it's usually easy to remember why you are there.) Now a new study from the University of Notre Dame says there's a very good reason why this forgetfulness occurs: walking through doorways causes our memories to lapse! Researcher Gabriel Radvansky explains why,

Entering or exiting through a doorway serves as an "event boundary" in the mind, which separates episodes of activity and files them away.

That means that by the time you've arrived in the kitchen and are staring at the counter, your brain has already moved on from the thought that led you in there, and you can't always effectively backtrack:

Recalling the decision or activity that was made in a different room is difficult because it has been compartmentalized.

So it's like the brain is too efficient for it's own good—sticking thoughts back in the cabinet before you're done using them. Maybe the best solution is to live in a studio apartment or a giant open loft with no doors—that way you'll have no "event boundaries" and can convince yourself you have a wonderful memory.